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Classifications

B—PERFORMING OPERATIONS; TRANSPORTING

B60—VEHICLES IN GENERAL

B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT

B60W40/00—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models

B60W40/02—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models related to ambient conditions

B60W40/06—Road conditions

B60W40/064—Degree of grip

B—PERFORMING OPERATIONS; TRANSPORTING

B60—VEHICLES IN GENERAL

B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES

B60T8/17—Using electrical or electronic regulation means to control braking

B60T8/1755—Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve

B—PERFORMING OPERATIONS; TRANSPORTING

B60—VEHICLES IN GENERAL

B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT

B60W30/00—Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units, or advanced driver assistance systems for ensuring comfort, stability and safety or drive control systems for propelling or retarding the vehicle

B60W30/02—Control of vehicle driving stability

B60W30/045—Improving turning performance

B—PERFORMING OPERATIONS; TRANSPORTING

B60—VEHICLES IN GENERAL

B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT

B60W40/00—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models

B60W40/10—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models related to vehicle motion

B60W40/103—Side slip angle of vehicle body

B—PERFORMING OPERATIONS; TRANSPORTING

B60—VEHICLES IN GENERAL

B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES

B60T2230/04—Jerk, soft-stop; Anti-jerk, reduction of pitch or nose-dive when braking

B—PERFORMING OPERATIONS; TRANSPORTING

B60—VEHICLES IN GENERAL

B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT

B60W2520/00—Input parameters relating to overall vehicle dynamics

B60W2520/10—Longitudinal speed

B—PERFORMING OPERATIONS; TRANSPORTING

B60—VEHICLES IN GENERAL

B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT

B60W2520/00—Input parameters relating to overall vehicle dynamics

B60W2520/12—Lateral speed

B60W2520/125—Lateral acceleration

B—PERFORMING OPERATIONS; TRANSPORTING

B60—VEHICLES IN GENERAL

B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT

B60W2520/00—Input parameters relating to overall vehicle dynamics

B60W2520/14—Yaw

B—PERFORMING OPERATIONS; TRANSPORTING

B60—VEHICLES IN GENERAL

B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT

B60W2520/00—Input parameters relating to overall vehicle dynamics

B60W2520/28—Wheel speed

B—PERFORMING OPERATIONS; TRANSPORTING

B60—VEHICLES IN GENERAL

B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT

Abstract

The present invention adjusts the amount of control yaw moment in accordance with a change in the dynamics of a vehicle including an abnormal vehicle acceleration / deceleration state.

A motion control apparatus for a vehicle having control means for controlling a yaw moment of the vehicle, comprising: first detecting means for detecting a speed V in the front and rear direction of the vehicle, and an acceleration force Gy_dot in the horizontal direction of the vehicle; A vehicle which has a second detecting means for detecting the yaw angle acceleration (r_dot) of the vehicle and a third detecting means for detecting the lateral acceleration Gy_dot of the vehicle detected by the second detecting means with the first detecting means. The yaw moment of the vehicle is controlled by the control means so that the difference between the value (Gy_dot / V) divided by the front-rear direction speed (V) and the yaw angle acceleration r_dot of the vehicle detected by the third detecting means becomes smaller.

Description

Motion control device of vehicle using acceleration information {MOTION CONTROL DEVICE FOR VEHICLE USING INFORMATION ADDED ACCELERATION}

The present invention relates to an apparatus for controlling the yaw moment by controlling the movement of the vehicle, in particular, the acceleration information in the transverse direction of the vehicle.

Regarding the vehicle control apparatus for controlling the yaw moment of the vehicle, there is a system disclosed in Patent Document 1, for example. However, in general, by generating a torque difference between the left and right wheels of the vehicle, the magnitude of the driving force or braking force exerted between the left and right wheels and the road surface is left and right unbalanced, thereby generating a yaw moment in the vehicle. To control the behavior of the vehicle.

Regarding the control logic for determining the target value of the torque difference generated between the left and right wheels of the vehicle, one of the methods disclosed in Patent Literature 1 is a method in which a value proportional to the steering wheel angular velocity is used as the target value of the torque difference. According to Patent Literature 1, when a torque difference proportional to the steering wheel angular velocity is generated, a yaw moment proportional to the steering wheel angular velocity is generated, thereby improving the initial response of the yaw motion of the vehicle to the steering wheel operation.

[Patent Document 1]

Japanese Patent Application Laid-Open No. 10-16599

However, as in the control logic disclosed in Patent Document 1, the target value of the torque difference generated between the left and right wheels of the vehicle is set to a value proportional to the steering wheel angular speed. There is no guarantee to cope with the change in motor performance.

As the speed of the vehicle increases, the stability of yaw response decreases, the tire reaches the nonlinear region due to the state of the vehicle sliding sideways, the load change of each wheel caused by acceleration and deceleration, or the lateral force increases due to the increase of the front and rear force of the tire. In the event of a decrease in force or the like, the restoration yaw moment originally possessed by the vehicle is changed. This restoring yaw moment and the combined yaw moment of the control input result in an area that makes the vehicle unstable.

An object of the present invention is to provide a motion control apparatus for a vehicle that can change the yaw moment control amount in accordance with a change in the dynamics of the vehicle.

In order to solve the said subject, this invention mainly employ | adopts the following structures.

A motion control apparatus for a vehicle having control means for controlling a yaw moment of the vehicle, comprising: first detecting means for detecting a speed V in the front and rear direction of the vehicle, and an acceleration force Gy_dot in the horizontal direction of the vehicle; A value obtained by dividing the acceleration (Gy_dot) in the transverse direction of the vehicle detected by the second detection means by the speed (V) in the front-back direction of the vehicle detected by the first detection means (Gy_dot /). Based on V), the yaw moment of the vehicle is controlled.

In addition, in the motion control apparatus of the vehicle, the vehicle has a third detecting means for detecting the yaw angle acceleration (r_dot) of the vehicle, and the acceleration (Gy_dot) in the lateral direction of the vehicle is the speed (V) in the front-rear direction of the vehicle. The yaw moment of the vehicle is controlled by the control means so that the difference between the value Gy_dot / V divided by and the yaw angle acceleration r_dot of the vehicle detected by the third detecting means becomes small.

According to the present invention, it is possible to adjust the control yaw moment amount in accordance with the change in the transverse dynamics of the vehicle including the abnormal vehicle acceleration / deceleration state, thereby achieving stable running.

Hereinafter, the motion control apparatus of the vehicle will be described in detail with reference to FIGS. 1 to 10. 1 is a view showing the overall configuration of a motion control apparatus of a vehicle. In the present embodiment, the vehicle 0 is constituted of a so-called biwire system, and there is no mechanical coupling between the driver and the steering mechanism, the acceleration mechanism, and the reduction mechanism. Next, the configuration and operation of the motion control apparatus for the vehicle according to the present embodiment will be described by dividing each item.

"Driving"

The vehicle 0 is a rear motor rear drive (RR car) which drives the left rear wheel 63 and the right rear wheel 64 by the motor 1 (in particular, the driving method is directly related to this embodiment). Is not). A driving force distribution mechanism 2 which is connected to the motor 1 and can freely distribute the torque of the motor to the left and right wheels is mounted.

First, the specific device configuration will be described. On the left front wheel 61, the right front wheel 62, the left rear wheel 63, and the right rear wheel 64, a brake rotor, a wheel speed detection rotor, and a wheel speed pickup are mounted on the vehicle side, It is the structure which can detect the wheel speed of each wheel. The amount of stepping of the driver's accelerator pedal 10 is detected by the accelerator position sensor 31 and arithmeticly processed by the central controller 40 via the pedal controller 48. During this arithmetic processing, the token distribution information according to the yaw moment control according to the present embodiment is also included. And the power train controller 46 controls the output of the motor 1 according to this control amount. In addition, the output of the motor 1 is distributed to the left rear wheel 63 and the right rear wheel 64 at an optimum ratio via the driving force distribution mechanism 2 controlled by the power train controller 46.

An accelerator reaction force motor 51 is further connected to the accelerator pedal 10, and reaction force control is performed by the pedal controller 48 based on a calculation command of the central controller 40.

"braking"

A brake rotor is provided on the left front wheel 51, the right front wheel 51, the left rear wheel 53, and the right rear wheel 54, respectively, and on the vehicle body side, the wheel is decelerated by fitting the brake rotor with a pad (not shown). The caliper to make it is mounted. The caliper is hydraulic or electric with an electric motor per caliper.

Each caliper is basically controlled by the brake controller 451 (for the front wheel) and the brake controller 452 (for the rear wheel) based on the calculation instruction of the central controller 40. The brake speeds of the respective wheels are input to the brake controllers 451 and 452 as described above. The absolute vehicle speed can be estimated by averaging the wheel speeds of the front wheels (non-drive wheels) with these four wheel speeds.

In the present embodiment, the absolute vehicle speed V is accurately measured even when the wheel speed drops at the same time as the four wheels by using the signals of the acceleration sensor that detects the wheel speed and the acceleration in the front and rear directions of the vehicle. Regarding the measurement of the vehicle speed, for example, a technique disclosed in Japanese Patent Laid-Open No. 5-16789 may be adopted. Further, the yaw rate of the vehicle body is estimated by taking the difference between the left and right wheel speeds of the front wheels (non-drive wheels) (r_w). These signals are always monitored as shared information in the central controller 40.

The brake reaction force motor 52 is connected to the brake pedal 11, and reaction force control is performed by the pedal controller 48 based on the calculation command of the central controller 40.

`` Integrated control of braking and driving ''

In this embodiment, when realizing yaw moment control described later, three modes (as described later, yaw moments by steering, yaw moments by left and right differential driving inputs, and yaw by loads moving from the rear wheels to the front wheels are described. Moment addition (see Fig. 7)], and one of them is &quot; addition of yaw moment by left and right differential driving input &quot;. Different braking force and driving force are generated in the left and right wheels, but it is the difference between the right and left braking force or driving force that contributes as the yaw moment.

Therefore, in order to realize this difference, there may be other operations than usual, such as driving one side and braking the opposite side. In such a situation, the integrated control command is determined by the central controller 40 integrally, and the brake controller 451 (for the front wheel), the brake controller 452 (for the rear wheel), the powertrain controller 46, the motor (1) It is suitably controlled via the driving force distribution mechanism 2.

Steering

The steering system of the vehicle 0 has a four-wheel steering system, but has a steering-by-wire structure without a mechanical coupling between the steering angle of the driver and the tire bending angle. The steering system is composed of a front power steering 7 including a steering angle sensor (not shown), a steering 16, a driver steering angle sensor 33, and a steering controller 44. The steering amount of the driver's steering 16 is detected by the driver's steering angle sensor 33, and is processed by the central controller 40 via the steering controller 44. This calculation processing also includes a steering angle input according to yaw moment control according to the present embodiment. And the steering controller 44 controls the front power steering 7 and the rear power steering 8 according to this steering amount.

The steering reaction force motor 53 is connected to the steering 16, and reaction force control is performed by the steering controller 44 based on a calculation command of the central controller 40. The amount of stepping of the driver's brake pedal 11 is detected by the brake pedal position sensor 32 and arithmeticly processed by the central controller 40 via the pedal controller 48.

"sensor"

Next, the motion sensor group of this embodiment is demonstrated. As shown in FIG. 1, the lateral acceleration sensor 21, the front-back acceleration sensor 22, and the yaw rate sensor 38 (vehicle rotational speed) are arrange | positioned near the center point. Further, differential circuits 23 and 24 are mounted to differentiate the output of each acceleration sensor to obtain acceleration information. Further, a differential circuit 25 for differentiating the sensor output of the yaw rate sensor 38 to obtain the yaw angle acceleration signal is mounted.

In the present embodiment, as shown in the sensor in order to clarify the existence of the differential circuit, it is shown that the actual acceleration signal may be input directly to the central controller 40 to perform various calculation processing and then may perform differential processing. . Therefore, the yaw rate acceleration of the vehicle body may be obtained by performing differential processing in the central controller 40 using the yaw rate estimated from the wheel speed sensor described above. In addition, although an acceleration sensor and a differential circuit are used in order to obtain acceleration, you may use the known acceleration sensor (for example, refer Unexamined-Japanese-Patent No. 2002-340925).

Yaw moment control

Next, yaw moment control by the distribution of the left and right wheel driving force will be described with reference to FIGS. 2 and 3. In the present embodiment, a vehicle (eg, a yaw moment added by steering), a yaw moment added by left and right differential driving input input, and a yaw moment added by a load movement from the rear wheels to the front wheels are used. Control the yaw moment applied to 0). Fig. 2 is a schematic diagram showing a situation in which three types of yaw moment inputs are performed in a counterclockwise turning state of the vehicle. 3 is a schematic diagram showing a situation in which three kinds of negative yaw moment inputs are performed in a counterclockwise turning state of the vehicle.

FIG. 2 is a diagram showing three methods in the case of inputting a positive moment from the standard state shown in FIG. First, equations of the lateral motion and yawing (rotational) motion of the vehicle 0 in the standard state A are shown.

Where m is the mass of the vehicle (0), Gy is the horizontal acceleration applied to the vehicle (0), Fyf is the lateral force of two front wheels, Fyr is the lateral force of two rear wheels, M is the yaw moment, and Iz is the vehicle (0 Yaw moment of inertia, r_dot: yaw acceleration (r is yaw rate) of vehicle (0), lf: distance between vehicle (0) center point and front wheel axle, lr: distance between vehicle (0) center point and rear wheel axle. In the standard state, the yawing motion is balanced (the yaw moment is zero), and the angular acceleration is zero.

It is the state of (B) that "applied yaw moment by steering" was implemented in the standard state (A). Since the front wheel steering angle is increased by Δδf and the rear wheel is increased by the reverse Δδr as compared to the standard state of (A), the lateral force of the front two wheels increases from Fyf to Fysf, and the lateral force of the rear two wheels decreases from Fyr to Fyrf. Therefore, according to the above equation (2), a positive moment (Ms) occurs as shown in the following equation (3).

In addition, in the present embodiment, a four-wheel steering vehicle capable of steering rear wheels is assumed, but even a normal front-wheel steering vehicle can generate a positive moment.

Next, the braking force (-Fdrl) is applied to the left rear wheel 63, the driving force Fdrr to the right rear wheel 64, and the braking force (-Fdf) is applied to the left front wheel 61 from the standard state of (A). The moment is added by the left and right brake input. in this case,

Becomes Where d represents the left and right tread (distance between left and right wheels as shown). Also,

In this case, the yaw moment can be generated without generating acceleration and deceleration in the front-rear direction even if the vehicle is not a front wheel drive car (even if the right front wheel 62 is not driven in this example). That is, the yaw moment can be applied to the driver without discomfort.

Next, FIG. 2 (d) is a method of actively generating load movement from the rear wheel to the front wheel by applying a braking force, thereby reducing the restoring yaw moment of the vehicle, and consequently generating the yaw moment.

The phenomenon of the addition of the yaw moment due to this load movement is described in "Motor Vehicle Society Vol. 47, No. 12, 1993 pp. 54-60, Author's Shibahata et al., Disclosed in "Improvement of Vehicle Movement Performance by Control of Yaw Moment", in which the lateral force of the tire is proportional to the load, The yaw moment is proportional to the product of the lateral acceleration and the front and rear acceleration. This phenomenon occurs when the frictional source of the front wheel increases with the deceleration (-Gx) in the state of FIG. 2 (a) while the frictional source of the rear wheel decreases with the deceleration (-Gx). However, -Gx is

to be. Equation transformation to the point where the applied yaw moment is the product of lateral acceleration and front and rear acceleration is omitted.

This makes it possible to inject a positive yaw moment.

3 is a method of inputting a negative yaw moment in the same manner as the method shown in FIG. Since the same method as the input of the positive yaw moment of FIG. 2 is omitted, the steering reduces the steering angle, or steers the rear wheels in the same phase direction as the front wheels, and applies the driving force in the reverse direction and applies the load. In the movement, the rear wheel load is increased by accelerating, the rear wheel lateral force is relatively increased, and the front wheel lateral force is decreased to obtain a moment in the restoring direction (clockwise in Fig. 3 (b) (c) (d)). have.

As described above, the vehicle of the present embodiment can generate yaw moments in both yin and yang according to the command of the central controller 40. Next, the method of calculating the target yaw moment for the specific yaw moment command will be described in detail. In addition, the outline of the method of generating the yaw moment described above is introduced in various documents.

`` Vehicle Dynamics Background ''

As shown in FIG. 4, the situation which turns along the curve with a vehicle is assumed. In the curve represented by C (s) = (X (s), Y (s)) of the coordinate system (X, Y) fixed to the ground, s is the distance to the curve. If the curvature of the trajectory is κ (= 1 / ρ (ρ: turning radius)), κ is generally represented by the long parameter s of the arc along the trajectory, as shown in equation (8). to be.

That is, when there is a change in the angle dθ when the curve is advanced by the predetermined distance ds, this is called curvature κ (dθ / ds).

As is well known, the trajectory that a vehicle draws when steering the steering wheel at a constant angular speed at a constant vehicle speed is called a clausoid curve and is commonly used in road design. This curve is

The change rate of curvature is a constant curve with respect to the distance which advances. Therefore, if the vehicle runs on a closed curve at a constant speed (u),

And the time change of curvature seen from this vehicle is

This becomes constant (you may think of this as a substitution from a long parameter to a time parameter t). On the other hand, from the definition of curvature κ, κ (s) is expressed as in Expression (12).

This means that when the vehicle moves from s1 to s2 on the curve of curvature κ (s) to the side without a change in slipping sideways, the vehicle yaw angle is generated by ψ.

As shown in FIG. 5, the state where there is no change of the side slip is zero between the vector V of the tangential direction of the curve [the thick black curve representing C (s)] and the speed direction (one-dot chain line direction) of the vehicle are zero. Fig. 5 (a) or the angle β called the lateral slip angle is a constant state (Fig. 5 (b)), and in this state, the vehicle's revolution and rotation are cooperatively coincident with each other. I think it is an ideal state. In addition, it is necessary to pay attention to the fact that the yaw angle generated in this abnormal state is geometrically determined and has no direct relationship with the vehicle dynamics. In addition, the detail about the state shown in FIG. 5 is described, for example in "the movement and control of a vehicle", the book by Masabe Abe, the publication of Sanheedang, the 1st printing of July 10, 4, Chapter 3.

`` Derivation of normative moment ''

It takes time t1 t2 to move from s1 to s2 shown in FIG. 4, and the yaw rate r_ref of the vehicle in such an active state is

Becomes In addition, when the yaw acceleration (r_ref_dot) is obtained,

Becomes Here, the speed of the traveling direction of the vehicle is expressed as

If the acceleration in the front and rear direction of the vehicle is Gx,

Becomes In addition, when the acceleration in the horizontal direction of the vehicle is Gy, the vehicle is moving in the state in which there is no change of sliding sideways as shown in FIG.

and

There is a relationship. Time derivative of both sides gives the time change of curvature,

Becomes

Here, Gy_dot is the lateral acceleration of the vehicle. Substituting Equation 16, Equation 18, and Equation 19 into Equation 14,

Here, since the product of forward and backward acceleration and lateral acceleration in claim 2 divided by the power of two is smaller than in claim 1, it is not considered in this embodiment. In addition, you may consider the case where a higher precision value is calculated | required.

Incidentally, the above equation (20) is the yaw angle acceleration required by the vehicle traveling in the abnormal state. If the yaw moment of inertia Iz of the vehicle is multiplied by the value of the yaw acceleration, it becomes the norm yaw moment (generally corresponding to the relationship between the force f = mass m x acceleration α).

`` Control logic ''

Next, a method of controlling the yaw moment of the vehicle in driving by using the above-described norm yaw moment will be described. Here, the norm moment is a moment required to find a path in a state in which the vehicle's revolution and rotation are coordinated and coincided with each other, and when the moment is large, the vehicle rotates, and when it is small, the vehicle moves away from the path. do.

As shown in FIG. 6, the actual vehicle has a difference between an orbital motion and a rotational motion. This is because the vehicle has dynamics and its characteristics change according to speed change, load change, disturbance, and the like. In this embodiment, the correction (deviation shown in FIG. 6) is considered to be corrected. Specifically, the following two cases are assumed. First, when entering the turning from a straight line or in the transient state of straight escape from the turning, the lateral acceleration with respect to the yaw rate has a response delay as a change in the lateral slip angle. Escape Assist). In addition, another consideration is given to the suppression of the (spin) state in which the balance of the lateral force of the front and rear wheels is broken for some reason and the rotation increases rather than the revolution (resistance change).

The output angular acceleration of the differential circuit 25 is referred to as r_real_dot for the yaw rate estimated from the difference between the yaw rate sensor 38 mounted on the vehicle 0 or the left and right wheel speed sensors. By multiplying this value by the yawing moment of inertia Iz of the vehicle 0, it is possible to grasp the yaw moment acting on the current vehicle.

As a result, the difference between the acting yaw moment (Iz · r_real_dot) and the normative yaw moment (Iz · r_ref_dot) becomes the difference yaw moment causing the difference between the revolution and the rotation. therefore

This is the yaw moment to be corrected. Where k is proportional gain. As a reason for requiring proportional gain, since the norm yaw moment does not include dynamics, there is an area to diverge when direct feedback (k = 1) is applied. Therefore, it is necessary to adjust k to be 1 or less necessarily.

Control logic configuration

7 is a schematic diagram showing the configuration of control logic according to the present embodiment. The yaw moment of the vehicle is controlled based on the value (Gy_dot / V) obtained by dividing the acceleration (Gy_dot) in the transverse direction of the vehicle by the speed (V) in the front-rear direction of the vehicle. The yaw moment of the vehicle is detected and the yaw moment of the vehicle is controlled so that the difference between (Gy-dot / V) and (r_dot) becomes small.

In addition, the conversion or combination of "adding yaw moment by steering", "adding yaw moment by left and right differential driving input input" and "adding yaw moment by moving load from the rear wheel to the front wheel" is determined according to the driver's input. do. For example, when there is an accelerator input, it does not perform "addition of the yaw moment by a load movement" according to deceleration, or controls the sum total of the "left-right differential drive input" according to an accelerator input of a driver. These series of processes are performed in the central controller 40.

"Confirmation of validity of principle by actual detection result"

Next, the detection test result of the correction yaw moment (DELTA) M using an actual difference is shown. The experimental vehicle is a passenger car of a front engine front drive of about 1500 [kg] and yawing inertia moment 2500 "kg m2", and has a transverse acceleration detection means and a yaw angle acceleration detection means.

Fig. 8 shows the trajectory of the vehicle when a driver performs a line trace task (left side in the drawing, (d) → (a)) and a voluntary drive (right side, (b) → (d)) for freely selecting a route. Measured values), the front and rear of the vehicle, the lateral acceleration, and the normative yaw acceleration (r_ref_dot) obtained by dividing the lateral acceleration at that time by the speed, the actual yaw acceleration (r_rea1_dot), and the difference between the respective angular accelerations. On the left side of the test track, approximately X = -100 [m], a line to be traced is drawn on the road surface.

Thus, the driver approaches the right corner from the side where X = 0 [m]. The moment of escape from the left corner is near 75 [s (Time)] in the following two graphs, where the vehicle enters (b) corner, (c) exits corner and back to (d) corner. Initiate a task.

The speed just before entry into the line trace task (left) corner is defined as approximately 60 [km / h], but the driver may use the brake and the accelerator freely. This is the acceleration graph shown in FIG. 8 second. Therefore, it should be noted that this experiment is the result of free acceleration and deceleration.

As can be estimated from Equation 20 above, the yaw acceleration and the time change of the curvature? Are highly correlated. Therefore, at corner entrances that trace lines with curvature changes, the normative yaw acceleration occurs. As shown in the third of Fig. 8, it can be seen that the difference between the standard yaw acceleration and the actual yaw acceleration is very small, and the driver traces the line accurately by controlling the vehicle without causing a large change in behavior.

Here, the lowest figure of FIG. 8 shows the correction yaw moment. Although it is a small amount as a whole, it is negative in positive and negative until the retardation acceleration of the norm increases and reaches a peak, and this value is fed back by multiplying the appropriate gain (k) as shown in Equation 21. It is clear that the instantaneous and convergence of the vehicle movement can be improved by the addition of. As described above, the present experiment is an experiment in which the driver is allowed free acceleration and deceleration by the brake and the accelerator. Therefore, the present embodiment is also effective in an abnormal vehicle acceleration / deceleration state.

In the case where the closed control is performed by the driver, since the driver performs the control precisely by consecutively braking, steering and acceleratoring, the correction yaw moment is often unnecessary. Conversely, in such a situation, the intervention of control increases the sense of discomfort. For this reason, in order to more clearly confirm the justification of the control logic (calculation of the correction yaw moment), an open loop test is performed in which a sinusoidal shape is steered at right and left at a set speed to determine whether an accurate correction yaw moment signal is calculated. I tried to verify whether or not.

Fig. 9 shows steering at a vehicle speed of 20 [km / h], 60 [km / h], and 80 [km / h], with 40 [deg], 40 [deg], 50 having a sine curve of 1 [Hz]. In the case of steering by [deg], it is a drawing comparing the normal yaw acceleration obtained by dividing the lateral acceleration by the speed and the actual yaw acceleration obtained by differentiating the yaw rate of the actual vehicle.

As is well known, the kinetic performance (dynamics) in the transverse direction of the vehicle changes depending on the vehicle speed. In actual yaw acceleration, the gain is low when the vehicle speed is slow, and the phase is delayed. As the vehicle speed increases, the gain increases, and accordingly, the phase delay also appears to be smaller (actually delayed). In such a case, the correction yaw moment also needs to change according to the vehicle speed.

On the other hand, the norm yaw acceleration stops steering, that is, the sinusoidal shape of 1 [Hz], and there is no phase delay due to the speed change (because vehicle dynamics is not used). Therefore, although FIG. 10 shows the correction yaw moment signal (DELTA) M calculated | required from the difference of norm yaw acceleration and actual yaw acceleration, it is clear that it is a correction amount containing dynamics change with respect to the norm yaw moment.

"theorem"

The configuration and functions of the vehicle motion control apparatus according to the present embodiment described above are summarized as follows. That is, a value obtained by dividing the acceleration (Gy_dot) in the transverse direction of the vehicle by the velocity (V) in the front and rear direction of the vehicle (Gy_dot / V = r_ref_dot) (normative yaw acceleration) and the vehicle's yaw acceleration detected by the vehicle's yaw acceleration detection means. Take the difference of the yaw acceleration (r_real_dot), and make this value smaller,

(1) controlling the lateral slip angle of each wheel of the vehicle to control the difference between the lateral force of the front wheel and the rear wheel,

(2) The longitudinal slip ratio of each wheel of the vehicle is controlled to generate the driving or braking torque difference of the left and right wheels (the longitudinal slip ratio is controlled to change the longitudinal force (front and rear force) of each wheel). Naturally, but is known in the art)

(3) By using three methods of changing the difference in the lateral force of the front and rear wheels by the load movement between the front and rear wheels due to the front and rear acceleration (in addition to applying the three control methods individually, these control methods are appropriately combined Of course, by controlling the yaw moment of the vehicle, it is possible to adjust the amount of control yaw moment in accordance with the change of the dynamics of the vehicle including an abnormal vehicle acceleration / deceleration state, thereby achieving stable running. have. In short, the main feature of the present invention is that the value obtained by dividing the acceleration in the transverse direction by the front-rear speed of the vehicle is multiplied by the yaw acceleration (the yaw inertia moment Iz) required to realize the motion shown in FIG. Lower yaw moment], and controls the yaw moment based on the difference between the actual yaw angle acceleration (r_real) and the divided value (r_ref).

Next, the motion control apparatus of the vehicle which concerns on other embodiment is demonstrated below. As shown in FIG. 7, the control apparatus in the above embodiment employs feedback and closed loop control based on the difference between the normal yaw rate of the vehicle and the actual yaw rate.

On the other hand, in another embodiment, open-loop control, especially yaw moment control by load movement, is employ | adopted. As described above, the Society of Automotive Engineers, Vol. 47, No. 12, 1993, pp. 54 to 60, published in "Improvement of Vehicle Movement Performance by Yaw Moment Control", in the range where the lateral force of the tire is proportional to the load, The yaw moment Mzls due to the acceleration and deceleration in rotation is proportional to the product of the lateral acceleration and the front and rear acceleration, as shown in equation (22). Where m is the vehicle mass, h is the center point height, and g is the gravitational acceleration.

Therefore, a value obtained by dividing the acceleration (Gy_dot) in the transverse direction of the vehicle by the velocity (V) in the front and rear direction of the vehicle (Gy_dot / V = r_ref_dot) times the moment of inertia around the z axis is required. Find the front and rear acceleration that realize the same control moment as the yaw moment and profile. This may be regarded as an integrated control of forward and backward motion and horizontal motion, in which the front and rear acceleration is determined by the brake accelerator according to the lateral acceleration and the lateral acceleration generated by the steering operation.

In other words, according to the driver's steering, the system automatically obtains a value that serves as a control guide for operating the brake accelerator. If the proportional constant is c, the command G acceleration and acceleration Gxc is given by the following expression (23).

By controlling the brake accelerator on the basis of this Gxc value, the moment due to the load movement is generated to be close to the normal yaw moment, so that the degree of coincidence between rotation and revolution increases to improve the maneuverability and stabilize the vehicle. Can be.

In the case where the vehicle is mounted on a vehicle, when the vehicle is divided by the lateral acceleration Gy, in the initial stage of turning, the lateral acceleration becomes a small value, and the acceleration before and after the command Gxc may be a large value. . Moreover, there exists a similar concern also when the speed has fallen. In order to avoid such a situation, as shown by Equation (24), main information is obtained from the acceleration in the transverse direction of the vehicle (Gy_dot), and the rest of the information is obtained from the speed, the lateral acceleration, or both functions f (Gy, V) or the acceleration Gxc before and after the command is determined as a gain KGyV stored in a map or the like together with the accompanying information, which is sufficiently engineeringally useful.

Specifically, the vehicle has means for detecting the speed V in the front and rear directions of the vehicle and the acceleration acceleration Gy_dot in the horizontal direction of the vehicle, and detects the horizontal acceleration Gy_dot of the detected vehicle. Based on the value (Gy_dot / V) divided by the speed V in the front-rear direction of the vehicle, the front and rear acceleration of the vehicle is controlled to control the yaw moment of the vehicle by moving the load. More specifically, the transverse acceleration Gy of the vehicle is detected, and the value obtained by dividing the acceleration (Gy_dot) in the transverse direction of the vehicle based on the detection by the velocity (V) in the front and rear directions detected by the vehicle (Gy_dot / V). ), The yaw moment of the vehicle is controlled by the load movement by controlling the forward and backward acceleration of the vehicle based on the physical quantity proportional to the value divided by the lateral acceleration Gy of the vehicle.

1 is a diagram showing the overall configuration of a motion control apparatus for a vehicle;

FIG. 2 is a schematic diagram showing a situation in which three types of yaw moment inputs are performed in a counterclockwise turning state of the vehicle;

3 is a schematic diagram showing a situation in which three types of negative yaw moment inputs are performed in a counterclockwise turning state of the vehicle;

4 is a view for explaining the concept of the curvature of the trajectory and the long arc parameter according to the trajectory in order to show the situation that the vehicle is turning along the curve;

Fig. 5 is a diagram showing an ideal state in which the vehicle shows a turning state without slipping laterally;

FIG. 6 is a view for explaining a situation in which an actual vehicle turns with dynamics and requires a correction yaw moment; FIG.

7 is a diagram for explaining control logic in a motion control apparatus of a vehicle;

8 is a diagram showing actual results at the time of exercise involving acceleration and deceleration in a vehicle;

9 is a view showing actual results of the norm yaw acceleration and actual yaw acceleration when the vehicle speed and steering conditions are defined;

It is a figure which shows the actual comparison of the target yaw moment and the correction yaw moment at the time of defining vehicle speed and steering conditions.

Claims (10)

In the motion control apparatus of a vehicle having a control means for controlling the yaw moment of the vehicle,

First detection means for detecting the speed V in the front and rear directions of the vehicle, and second detection means for detecting the acceleration Gy_dot in the horizontal direction of the vehicle,

On the basis of the value (Gy_dot / V) obtained by dividing the acceleration (Gy_dot) in the transverse direction of the vehicle detected by the second detection means by the velocity (V) in the front-rear direction of the vehicle detected by the first detection means. Motion control device of the vehicle, characterized in that for controlling the yaw moment.

The method of claim 1,

Having third detecting means for detecting the yaw angle acceleration (r_dot) of the vehicle,

The difference between the acceleration (Gy_dot) in the horizontal direction of the vehicle divided by the velocity (V) in the front-rear direction of the vehicle (Gy_dot / V) and the yaw angle acceleration (r_dot) of the vehicle detected by the third detection means is small. To control the yaw moment of the vehicle by the control means.

The method of claim 1,

And the control means for controlling the yaw moment of the vehicle controls the difference between the lateral force of the front wheel and the rear wheel by changing the lateral slip angle of each wheel of the vehicle.

The method of claim 1,

The control means for controlling the yaw moment of the vehicle is to change the longitudinal slip ratio of each wheel of the vehicle to generate a driving force difference or a braking force difference of the left and right wheels.

The method of claim 1,

The control means for controlling the yaw moment of the vehicle generates front and rear forces by varying the longitudinal slip ratio of each wheel of the vehicle while the lateral acceleration is acting on the vehicle, thereby generating the front and rear forces. A motion control device for a vehicle, characterized by generating front and rear forces of opposite load movement and changing the difference between the lateral forces of the front and rear wheels.

First detecting means for detecting the speed V in the front-rear direction of the vehicle, second detecting means for detecting the acceleration Gy in the lateral direction of the vehicle, and detecting yaw rate of the vehicle. Having third detecting means,

Differentiate the acceleration Gy in the horizontal direction detected by the second detecting means to obtain the acceleration (Gy_dot) in the horizontal direction of the vehicle,

A value (Gy_dot / V = r_ref) obtained by dividing the obtained acceleration (Gy_dot) in the transverse direction of the vehicle by the speed (V) in the front and rear direction of the vehicle detected by the first detection means,

The yaw rate detected by the third detecting means is differentiated to calculate the yaw rate acceleration (r_real),

Obtaining a correction yaw moment based on the difference between the calculated value r_ref and the yaw angle acceleration r_real,

Based on the obtained correction yaw moment, the yaw moment added by any one of the yaw moment added by steering, the yaw moment added by the left and right differential brake driving input, the yaw moment added by the load movement from the rear wheel to the front wheel, or any one Motion control apparatus for a vehicle, characterized in that for controlling the yaw moment applied to the vehicle by using a combination of the yaw moment.

In the motion control apparatus of a vehicle having a control means for controlling the front and rear acceleration of the vehicle,

First detection means for detecting the speed V in the front and rear directions of the vehicle, and second detection means for detecting the acceleration Gy_dot in the horizontal direction of the vehicle,

On the basis of the value (Gy_dot / V) obtained by dividing the acceleration (Gy_dot) in the transverse direction of the vehicle detected by the second detection means by the speed (V) in the front and rear direction of the vehicle detected by the first detection means, Motion control device for a vehicle, characterized in that for controlling the front and rear acceleration of the vehicle.

The method of claim 7, wherein

The vehicle has third detecting means for detecting the lateral acceleration Gy of the vehicle,

Obtaining an acceleration Gy_dot in the transverse direction of the vehicle based on the lateral acceleration Gy detected by the third detection means,

With respect to the value Gy_dot / V obtained by dividing the obtained acceleration Gy_dot in the lateral direction of the vehicle by the speed V in the front-rear direction detected by the first detection means, the third detection means And the front and rear acceleration of the vehicle is controlled on the basis of the physical quantity proportional to the value divided by the detected lateral acceleration (Gy) of the vehicle.

In the motion control apparatus of a vehicle having a control means for controlling the front and rear acceleration of the vehicle,

Means for detecting the acceleration (Gy_dot) in the transverse direction of the vehicle,

And the front and rear acceleration of the vehicle on the basis of the acceleration (Gy_dot) in the transverse direction of the vehicle detected by the detecting means.

The method of claim 9,

And the front and rear acceleration of the vehicle is controlled to be closer to the value obtained by multiplying the acceleration (Gy_dot) in the transverse direction of the vehicle by the coefficient.